scholarly journals Interaction of nistranol with estradiol and progesterone receptors in the rat uterus cytosol in vitro and in vivo

1996 ◽  
Vol 42 (4) ◽  
pp. 33-34
Author(s):  
Ye. N. Kareva ◽  
V. P. Fedotov ◽  
V. M. Rzheznikov ◽  
Ye. V. Solovyova ◽  
Ye. V. Pokrovskaya

Interactions between nistranol and estradiol and progesterone receptors in the cytosol fraction of the uterine tissue of oophorectomized rats and the relative competitive capacity of nistranol have been studied 24 h after a single injection of the drug. The results demonstrate the effects of nistranol on estradiol and progesterone binding. Nistranol boosting of uterine growth in rats is explained by its capacity to accelerate the translocation of hor- mone-receptor complexes into the nucleus. Investigations of the capacity of new estrogens to compete with estradiol for binding in the tissues of target organs in vitro and affect estradiol and progesterone binding in vivo permit a more effective screening of estrogens than use of only the classical in vitro method.

2013 ◽  
Vol 100 (3) ◽  
pp. S126
Author(s):  
K. Miyazaki ◽  
T. Maruyama ◽  
H. Masuda ◽  
N. Hida ◽  
H. Uchida ◽  
...  

1983 ◽  
Vol 50 (02) ◽  
pp. 518-523 ◽  
Author(s):  
C Kluft ◽  
A F H Jie ◽  
R A Allen

SummaryFunctional assay of extrinsic (tissue-type) plasminogen activator (EPA) in plasma on fibrin plates was evaluated. Using specific quenching antibodies, we demonstrated the method to be specific for EPA under all conditions tested. Contributions of urokinases and intrinsic activators were excluded. The quantity of EPA in blood samples, as compared with purified uterine tissue activator, shows 1 blood activator unit (BAU) to be comparable to 0.93 ng.The median values for EPA activity for healthy volunteers were: baseline, 1.9 BAU/ml (n = 123); diurnal, 5.5 BAU/ml (n = 12); DDAVP administration, 11.7 BAU/ml (n = 39); exhaustive exercise, 25 BAU/ml (n = 24); venous occlusion (15 min), 35 BAU/ml (n = 61). A large inter-individual variation in EPA activity was found, while individual baseline values tended to be constant for periods of weeks.In vitro in blood EPA activity shows a disappearance of 50% in about 90 min at 37° C; EPA activity in euglobulin fractions is stable for ≤2 hr at 37° C.A rapid decrease in EPA activity occurs in vivo, as noted after extracorporal circulation and exercise stimulation (t½ decay, 2-5 min).


2019 ◽  
Vol 18 (9) ◽  
pp. 1289-1294 ◽  
Author(s):  
Kusum Vats ◽  
Rohit Sharma ◽  
Haladhar D. Sarma ◽  
Drishty Satpati ◽  
Ashutosh Dash

Aims: The urokinase Plasminogen Activator Receptors (uPAR) over-expressed on tumor cells and their invasive microenvironment are clinically significant molecular targets for cancer research. uPARexpressing cancerous lesions can be suitably identified and their progression can be monitored with radiolabeled uPAR targeted imaging probes. Hence this study aimed at preparing and evaluating two 68Ga-labeled AE105 peptide conjugates, 68Ga-NODAGA-AE105 and 68Ga-HBED-CC-AE105 as uPAR PET-probes. Method: The peptide conjugates, HBED-CC-AE105-NH2 and NODAGA-AE105-NH2 were manually synthesized by standard Fmoc solid phase strategy and subsequently radiolabeled with 68Ga eluted from a commercial 68Ge/68Ga generator. In vitro cell studies for the two radiotracers were performed with uPAR positive U87MG cells. Biodistribution studies were carried out in mouse xenografts with the subcutaneously induced U87MG tumor. Results: The two radiotracers, 68Ga-NODAGA-AE105 and 68Ga-HBED-CC-AE105 that were prepared in >95% radiochemical yield and >96% radiochemical purity, exhibited excellent in vitro stability. In vivo evaluation studies revealed higher uptake of 68Ga-HBED-CC-AE105 in U87MG tumor as compared to 68Ga-NODAGAAE105; however, increased lipophilicity of 68Ga-HBED-CC-AE105 resulted in slower clearance from blood and other non-target organs. The uPAR specificity of the two radiotracers was ascertained by significant (p<0.05) reduction in the tumor uptake with a co-injected blocking dose of unlabeled AE-105 peptide. Conclusion: Amongst the two radiotracers studied, the neutral 68Ga-NODAGA-AE105 with more hydrophilic chelator exhibited faster clearance from non-target organs. The conjugation of HBED-CC chelator (less hydrophilic) resulted in negatively charged 68Ga-HBED-CC-AE105 which was observed to have high retention in blood that decreased target to non-target ratios.


2021 ◽  
Vol 7 (2) ◽  
pp. 113
Author(s):  
Anne-Laure Bidaud ◽  
Patrick Schwarz ◽  
Guillaume Herbreteau ◽  
Eric Dannaoui

Systemic fungal infections are associated with high mortality rates despite adequate treatment. Moreover, acquired resistance to antifungals is increasing, which further complicates the therapeutic management. One strategy to overcome antifungal resistance is to use antifungal combinations. In vitro, several techniques are used to assess drug interactions, such as the broth microdilution checkerboard, agar-diffusion methods, and time-kill curves. Currently, the most widely used technique is the checkerboard method. The aim of all these techniques is to determine if the interaction between antifungal agents is synergistic, indifferent, or antagonistic. However, the interpretation of the results remains difficult. Several methods of analysis can be used, based on different theories. The most commonly used method is the calculation of the fractional inhibitory concentration index. Determination of the usefulness of combination treatments in patients needs well-conducted clinical trials, which are difficult. It is therefore important to study antifungal combinations in vivo, in experimental animal models of fungal infections. Although mammalian models have mostly been used, new alternative animal models in invertebrates look promising. To evaluate the antifungal efficacy, the most commonly used criteria are the mortality rate and the fungal load in the target organs.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3532
Author(s):  
Ibrahim M. El-Deeb ◽  
Valeria Pittala ◽  
Diab Eltayeb ◽  
Khaled Greish

Triple-negative breast cancer (TNBC) is a heterogeneous subtype of tumors that tests negative for estrogen receptors, progesterone receptors, and excess HER2 protein. The mainstay of treatment remains chemotherapy, but the therapeutic outcome remains inadequate. This paper investigates the potential of a duocarmycin derivative, tafuramycin A (TFA), as a new and more effective chemotherapy agent in TNBC treatment. To this extent, we optimized the chemical synthesis of TFA, and we encapsulated TFA in a micellar system to reduce side effects and increase tumor accumulation. In vitro and in vivo studies suggest that both TFA and SMA–TFA possess high anticancer effects in TNBC models. Finally, the encapsulation of TFA offered a preferential avenue to tumor accumulation by increasing its concentration at the tumor tissues by around four times in comparison with the free drug. Overall, the results provide a new potential strategy useful for TNBC treatment.


1987 ◽  
Vol 36 (3) ◽  
pp. 397-400 ◽  
Author(s):  
Paul Galand ◽  
Nicole Mairesse ◽  
Chantal Degraef ◽  
Jacques Rooryck
Keyword(s):  

1976 ◽  
Vol 83 (3) ◽  
pp. 604-620 ◽  
Author(s):  
B. P. Lisboa ◽  
M. Holtermann

ABSTRACT In vitro experiments carried out with uterus preparations of ovariectomized adult rats indicate the presence in this tissue of a 20β-hydroxysteroid-oxidoreductase which catalyzes the conversion of 20β-hydroxy-4-pregnen-3-one to progesterone. Since a hepatic 20β-hydroxysteroid-oxidoreductase is absent in adult female rats, the myometrial enzyme can be responsible for the biological activity of 20β-hydroxy-4-pregnen-3-one in these animals. Besides progesterone five metabolites were isolated and identified after incubation of [4-14C]20β-hydroxy-4-pregnen-3-one with uterine tissue: 20β-hydroxy-5α-pregnan-3-one, 20β-hydroxy-5β-pregnan-3-one, 5α-pregnane-3α,20β-diol, 4-pregnene-3α,20β-diol and 4-pregnene-3β,20β-diol. The conversion of 20β-hydroxy-4-pregnen-3-one to progesterone permits us to regard all five steroids isolated as progesterone metabolites in the rat uterus. 20β-hydroxy-5β-pregnan-3-one is the first C21-metabolite with a 5β(H)-configuration isolated in the rat uterus, which indicates the presence of 5β-reductase in this tissue.


2009 ◽  
pp. 757-761
Author(s):  
CF Sharpley ◽  
KG Kauter ◽  
JR McFarlane

Cortisol is secreted by the central hypothalamo-pituitary-adrenal axis and affects many target organs and tissues, particularly in response to stressor demands and infection. Recent data reporting cortisol synthesis in hair follicles have shown the existence of a parallel “peripheral” HPA-axis. However, although there is evidence from in vitro studies and single-observation comparisons between groups that cortisol from hair follicles reflects endocrine changes associated with stressor demands, there are no reports to date of repeated measurements of in vivo cortisol responsivity in hair to transitory stressors. This issue was investigated with three males who underwent 1 min cold pressor test (CP). Cortisol response in hair to stressor demand appears to be (a) swift but transitory, (b) localized to the site of the demand and (c) independent of central HPA-axis activity.


1982 ◽  
Vol 94 (1) ◽  
pp. 111-123 ◽  
Author(s):  
Y. Koseki ◽  
M. E. Costlow ◽  
D. Cole ◽  
A. Matsuzawa

The binding of [3H] 17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione (R5020) to progesterone receptors in cytosol and nuclear extracts (0·6 m-KCl) of the pregnancy-dependent, TPDMT-4 mouse mammary tumour was measured at various stages of pregnancy. Compared with conventional dextran-coated charcoal (DCC) assays, a hydroxylapatite assay with DCC pretreatment and precharging of the cytosol with unlabelled R5020 (4 × 10−8 mol/l, for 3–4 h at 4 °C) showed the highest level of binding. The DCC treatment markedly increased the level of R5020 binding in both cytosol and nuclear extracts by allowing the receptor to bind to hydroxylapatite. The DCC pretreatment apparently removed a heat-stable and non-dialysable factor which prevented the receptor from binding to the hydroxylapatite. Using this assay R5020 binding reached a steady state in 24 h at 4 °C, with complete exchange of radioactive for non-radioactive ligand by 20 h. Nuclear extracts did not require precharging and complete exchange was more rapid. Scatchard analysis (without precharging) disclosed a single class of binding sites with a dissociation constant for cytosol of 3·2 ± 0·8 (s.e.m.) × 10−9 mol/l (n = 3) and 4·7 ± 0·6 × 10−9 mol/l (n = 5) for the nuclear extract. Binding was hormone-specific and progesterone translocated binding from the cytoplasm to the nucleus both in vivo and in vitro. Translocation, however, led to a substantial loss of total (nuclear + cytoplasmic receptors. During pregnancy, cytoplasmic progesterone receptor levels were unchanged and low compared to nuclear progesterone receptors which increased by sevenfold from days 1 to 11 and then decreased at day 16. Compared with recent data on cytoplasmic progesterone receptors in normal mammary gland, our results suggested that this tumour may have a reduced sensitivity to the down-regulatory activity of progesterone. This lesion may, in part, account for the failure of the tumour to differentiate during pregnancy.


2006 ◽  
Vol 19 (1) ◽  
pp. 205873920601900 ◽  
Author(s):  
F. Marcucci ◽  
L. Sensi ◽  
G. DI Cara ◽  
G. Gidaro ◽  
C. Incorvaia ◽  
...  

Oral Allergy Syndrome (OAS) in patients with pollen-induced rhinoconjunctivitis is caused by specific IgE recognizing cross-reacting epitopes of fruits and plants, which were clearly shown in vitro, but failed to be demonstrated in vivo by cross-challenges in the target organs. Considering the hypothesis of degradation of such epitopes in natural extracts, challenges with recombinant pollen allergens were done to evaluate the reactivity of the oral mucosa in OAS patients. Seventeen patients with OAS and rhinitis from birch (10) and grass pollen (7) and 10 non-atopic controls were studied by skin prick tests (SPT), allergen specific nasal challenges (ASNC) and allergen specific sublingual challenges (ASSC) with birch and timothy extracts and with rBet v1 and rPhl p1 at increasing concentrations from 1 to 1000 mcg/ml. None of the healthy subjects in the control group had any positive test for birch and timothy extracts or for recombinant allergens. In the OAS group the following results were observed: SPTs with recombinant allergens were positive in all patients, mostly at 10 mcg/ml concentration; ASNC with rBet v1 were positive in all patients, mostly at 100 mcg/ml; ASSC with natural pollen extracts were positive in only 2 of 17 patients, but in 15 of 17 with rBet v1 and rPhl p1, mostly at 500 mcg/ml and 1000 mcg/ml. ASSC with rBet v1 and rPhl p1 were positive with a mean concentration of 677 and 533 mcg/ml, respectively. The results of sublingual challenges with rBet v1 and rPhl p1 showed the in vivo cross-reactivity between pollens and foods in patients with OAS, but high concentrations of the recombinant allergens were needed to reproduce oral symptoms, thus explaining the failure of challenges performed with natural extracts, which have concentrations of major allergens lower than 50 mcg/ml. This indicates that sublingual mucosa is much less reactive to allergens than other surfaces, such as skin and nasal mucosa, probably because of its anatomic and immunologic peculiarity.


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